Increasing Tongue Weight on Nissan NV3500 (or in general)

So just one more question - is the tongue weight always 10% of the maximum towing capacity? I just ask because on the Passenger NV3500 the towing capacity is 8700 and the tongue weight capacity it 870 but on he NV3500 cargo I saw that the towing capacity is 9500 and the tongue capacity is 950. Just wondering for the sake of knowing.

Thanks for the insight!